diff --git a/backend/tests/test_common.c b/backend/tests/test_common.c
index e5d5d049..2a45248c 100644
--- a/backend/tests/test_common.c
+++ b/backend/tests/test_common.c
@@ -216,7 +216,7 @@ static void test_zero_fill(const testCtx *const p_ctx) {
     testStart(p_ctx->func_name);
 
     for (i = 0; i < data_size; i++) {
-        unsigned char dest[200];
+        unsigned char dest[20] = {0};
 
         if (testContinue(p_ctx, i)) continue;